Method for tamping ballast supporting track ties

ABSTRACT

In a method for tamping ballast supporting sequentially arranged ties of a track extending in a longitudinal direction, which comprises a tamping cycle at each one of the ties, the tamping cycle comprises lowering a tamping head carrying tamping tools hydraulicallly reciprocable in the longitudinal direction to immerse the tamping tools in the ballast, reciprocating the tamping tools to tamp the ballast, vibrating the tamping tools in a first tamping cycle phase, discontinuing vibration of the tamping tools in a second tamping cycle phase, raising the tamping head to lift the tamping tools out of the ballast, and moving the tamping head from tie to tie.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for tamping ballast supportingsequentially arranged ties of a track extending in a longitudinaldirection, which comprises a tamping cycle at each tie. Each tampingcycle comprises lowering a tamping head carrying tamping toolshydraulicallly reciprocable in the longitudinal direction to immerse thetamping tools in the ballast, reciprocating the tamping tools to tampthe ballast, vibrating the tamping tools, raising the tamping head tolift the tamping tools out of the ballast, and moving the tamping headfrom tie to tie.

2. Description of the Prior Art

Mobile track tampers with tamping heads for tamping ballast supportingtrack ties are well known, as exemplified by U.S. Pat. Nos. 4,068,595and 4,240,352, as well as Austrian patent No. 339,358 and EP 0 331 956.As disclosed in the prior art, the tamping tools may be vibrated by acrank drive or by hydraulic impulses applied to a linear drive used forthe reciprocation of the tamping tools.

SUMMARY OF THE INVENTION

It is the primary object of this invention to optimize the tampingmethod outlined hereinabove and to reduce the unfavorable influences ofthe vibrations.

The above and other objects are accomplished according to the inventionwith a tamping cycle in which the tamping tools are vibrated in a firsttamping cycle phase, and the vibration of the tamping tools isdiscontinued in a second tamping cycle phase.

This reduces the vibration of the tamping tools to the time when theyactually work to tamp the ballast, which means that they are subjectedto less wear caused by the vibrations while, at the same time, theenvironment is relieved of the very loud noise created by the vibratingtamping tools for up to about two third of the time during which thetamping tools were vibrated in conventional methods. In addition, theunpleasant vibrations to which operators are subjected in the operator'scab are greatly reduced.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, advantages and features of the presentinvention will become more apparent from the following detaileddescription of a now preferred embodiment thereof, taken in conjunctionwith the accompanying drawing wherein

FIG. 1 is a schematic side view of a substantially conventional tracktamper useful for carrying out the ballast tamping method of thisinvention;

FIG. 2 is an enlarged side view of the tamping head carried by the tracktamper; and

FIG. 3 illustrates the tamping cycle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIGS. 1 and 2, tamping head 1 is vertically movably mountedon frame 11 of mobile track tamper 12 arranged for mobility on track 14extending in a longitudinal direction and consisting of sequentiallyarranged ties 4 to which two track rails are fastened. A drive 13 movesthe track tamper from tie to tie in a direction indicated by arrow 5.

The tamping head comprises a carrier 7 whereon tamping tools 3,including tamping picks 2, are pivotally mounted. The tamping tools arespaced from each other in the longitudinal direction and are pivotalabout pivot axes 6 on carrier 7, upper ends of the tamping tools beinglinked to one end of linear reciprocating drives 8 for reciprocating thetamping tools in the longitudinal direction. The other end of eachreciprocating drive is linked to carrier 7 at 9. A drive 10 connects thetamping head carrier to frame 11 of the track tamper.

Linear reciprocating drives 8 are so constructed (as disclosed indetail, for example, in U.S. Pat. No. 4,068,595, Austrian patent No.339,358 and EP 0 331 956) that they effect not only a linearreciprocation of the tamping tools in a direction indicated by arrow 15but also vibrate tamping picks 2 by schematically illustrated vibrationdrives 18. The reciprocating drives have motion pickups 16 and arecontrolled by servo valves of a hydraulic installation (well known andnot illustrated) to set the velocity of the reciprocating motion and theamplitude, form and frequency of the vibrations.

FIG. 3 illustrates a tamping cycle according to the invention. Line ashows the raised state of tamping head 1 and tamping picks 2, in which,as shown in FIG. 2, tamping picks are raised above tie 4 so that tracktamper 12 may be moved without hindrance in the direction indicated byarrow 5. Line b shows the lowered state of tamping picks 2, wherein theyare immersed in the ballast for tamping ballast 17 embedding tie 4 fortamping the ballast underneath the tie by reciprocating the tampingpicks in the direction indicated by arrows 15. The lowest line tindicates the time of the tamping cycle and vibration frequency f.

The tamping cycle sz at each tie begins with the operation of drive 10to lower the tamping head from A to b to immerse the tamping tool picksin ballast 17. Subsequently, reciprocating drives 8 are operated toreciprocate the immersed tamping tool picks from B to C to tamp ballast17 between the reciprocating immersed tamping tool picks 2. After theballast has been tamped, tamping head 1 is raised from C to D to lifttamping tools 3 out of the ballast, and the tamping head is moved from Dto E to the next tie 4.

Parallel to the lowering of the tamping head, vibration drives 18 areoperated to vibrate tamping tools 3 in a first tamping cycle phase xduring which the tamping tools are lowered from A to B and reciprocatedfrom B to C, and the vibration of the tamping tools is discontinued in asecond tamping cycle phase y when tamping head 1 is raised at C andmoved from tie to tie from C to E. Thus, tamping cycle sz is comprisedof first tamping cycle phase x and a second tamping cycle phase y.

The tamping tools may be vibrated in the first tamping cycle phase insubsequent steps at differing vibration frequencies. Preferably, thetamping tools are vibrated during lowering of the tamping head at afrequency which is higher than the subsequent vibration frequency duringthe reciprocation of the tamping tools. The tamping head is raised andmoved from tie to tie in the second tamping cycle phase.

1. A method for tamping ballast supporting sequentially arranged ties ofa track extending in a longitudinal direction, which comprises a tampingcycle at each one of the ties, the tamping cycle comprising (a) loweringa tamping head carrying tamping tools hydraulically reciprocable in thelongitudinal direction to immerse the tamping tools in the ballast, (b)reciprocating the tamping tools to tamp the ballast, (c) vibrating thetamping tools in a first tamping cycle phase, (d) discontinuingvibration of the tamping tools in a second tamping cycle phase, (e)raising the tamping head to lift the tamping tools out of the ballast,and (f) moving the tamping head from tie to tie.
 2. The method of claim1, wherein the tamping tools are lowered and reciprocated to tamp theballast in the first tamping cycle phase.
 3. The method of claim 2,wherein the tamping tools are vibrated in the first tamping cycle phasein subsequent steps at differing vibration frequencies.
 4. The method ofclaim 4, wherein the tamping tools are vibrated during lowering of thetamping head at a frequency which is higher than the subsequentvibration frequency during the reciprocation of the tamping tools. 5.The method of claim 1, wherein the tamping head is raised and moved fromtie to tie in the second tamping cycle phase.